Grinding wheel dressing apparatus



Oct. 30, 1956 HOGLUND GRINDING WHEEL DRESSING APPARATUS 6 Sheets-Sheet 1Filed May 20, 1954 jams 5%.- /Y/45 #041 Mm Oct. 30, 1956 HOGLUNDGRINDING WHEEL DRESSING APPARATUS 6 Sheets-Sheet 2 Filed May 20, 1954 I.cllll I Z m%% MA: #044 m0 7mm 4% Oct. 30, 1956 Filed May 20. 1954 N.HOGLUND GRINDING WHEEL DRESSING APPARATUS 6 Sheets-Sheet 5 Oct. 30, 1956N. HOGLUND 2,768,619

GRINDING WHEEL DRESSING APPARATUS Filed May 20, 1954 6 Sheets-Sheet 4Oct. 30, 1956 I N. HOGLUND 2,768,619

GRINDING WHEEL DRESSING APPARATUS Filed May 20, 1954 s Sheets-Sheet s77M & 44 52% Oct. 30, 1 956 HOGLUND 2,768,619

GRINDING WHEEL DRESSING APPARATUS Filed May 20, 1954 6 Sheets-Sheet 6United States Patent GRINDING WHEEL DRESSING APPARATUS Nils Hoglund,Summit, N. J.

Application May 20, 195'4, Serial No. 431,065

9 Claims. (Cl. 125-11) My invention relates to apparatus for forming andmaintaining contours on grinding wheels, more particularly toimprovements in grinding wheel dressing apparatus.

In certain types of plain, cylindrical grinders no space is availablefor mounting a dresser either on the table of the machine or any otherplace conveniently. The only place where such a dresser can be supportedis between the centers of the grinder where the work piece is normallypositioned. However, if so mounted, the apparatus must be so constructedthat it can be easily positioned within and placed on or removed fromthe machine. A dresser of this character must not vary to any greatextent in weight as compared with the work piece and it must be topositioned that the dressing tools will occupy a position identical withthat of the contour being dressed on the work piece. In addition, thedresser must be extremely compact, must be properly balanced and must beadjustable in its position both between the centers of the grindingapparatus and in the plane in which the dresser is to be mounted. Inorder to provide the neces sary space within the dresser housing toinclude the template slide and ratio slides, the housing must be sodesigned and the slides must be so arranged as to their relationship asto obtain the movements desired of the housing and dressing tools while,at the same time, permitting the positioning of the dressing apparatusin the space available.

The principal object of my invention is to provide an improved grindingwheel dressing apparatus particularly suitable for use where space is ata premium and which can be quickly and easily positioned on the grindingwheel apparatus.

Another object of my invention is to provide a dressing apparatus whichcan be quickly and easily attached to or removed from a-grinder andparticularly which can be positioned between the centers on which thework piece is supported.

Another object of my invention is to provide such an apparatus that canbe easily and precisely adjusted to dressing position even thoughdetachable between dressing operations.

A further object of my invention is to provide a dressing apparatuswhich is compact, has weight comparable to a piece being ground andwhich can be substituted for the work piece when in dressing position.

Apparatus made according to my invention includes a bracket having ashelf and providing a base support, the bracket being provided with apair of female centers to position the dressing apparatus in the sameposition as the piece to be worked upon by the grinding mechanism. Thebase supports a slide guide upon which a tool housing is slidablysupported to move parallel to the axis of the grinding wheel to bedressed. The housing slidably supports a pair of dressing diamonds whichmove normally of the axis of the wheel being dressed and of the movementof the housing. The housing proper includes a plurality of slides andfollowers electrically drivenfor controlling movement of the housing andthe dressing tools. A main slide supporting the template and a ratio cammoves normally of the housing, the ratio cam contacting a fixed pinsupported on the base to control movement of the housing and thetemplate engaging the follower of an intermediate slide moving normallyof the main slide and parallel to the housing movement and in turncarrying a ratio cam. The dressing tools are mounted on a secondaryslide for movement normal of the movement of the housing and having afollower engaging the ratio cam on the intermediate slide.

in the drawings Fig. 1 is a front view perspective of a grinding wheeldressing apparatus made according to my invention;

Fig. 2 is a plan view of the bracket and base for sup porting the toolhousing of the device shown in Fig. 1;

Fig. 2a shows a detail of construction of Fig. 2;

Fig. 3 is a plan view with cover removed of the apparatus shown in Fig.1;

Fig. 4 is a section taken along the line 4-4 of Fig. 3;

Fig. 5 is a section taken along the line 55 of Fig. 3; and

Fig. 6 is a section taken along the line 66 of Fig. 3 with a portionbroken away to show details of construction.

Referring specifically to Fig. 1, a grinding wheel dressing apparatusmade according to my invention includes a bracket 10 having a head stockcenter 11 and a foot stock center 12, the foot stock center 12 having anadjustable tubular element or sleeve 12' which can be adjustedlongitudinally of the axis to fit between differently spaced centers,the bushing being split at 12" for locking the sleeve 12' in positionwhen properly adjusted by means of the screw 12".

The bracket 19 extends rearwardly of the stock centers to provide ashelf 1% for the base 13 and slide guide 31 which is shown in moredetail in other views. The housing 14 is slidably mounted onball-bearing assemblies to be described so as to have movement parallelto the axis of the wheel being ground.

Within the housing and extending therefrom toward the axis of thecenters are a pair of dressing tools or cuttingdiamonds 15 and it: whichare mounted on a slide to be described for movement in and out of thehousing normal to the movement of the housing which is parallel to theaxis of the wheel being dressed.

The prime mover for driving the various slides mounted within thehousing for controlling the movement of the housing and dressingdiamonds is the electrical motor 17 mounted on the cover of the housingand which operates in a manner to be described.

A pair of eye hooks 18 and 19 are secured to the bracket shelf so thatthe whole apparatus can be easily and quickly lifted on and off thegrinding equipment.

An adjusting screw or button 2% which contacts the grinding apparatus ismounted on the front of the bracket for adjusting the horizontalposition of the shelf. Details are shown in other views.

In operation the dressing apparatus is positioned between the centers onwhich the work piece is normally mounted so that the wheel which dressesthe contour on the work piece has the same relative position with andcan be contacted by the diamonds as the wheel takes relative to the workpiece during operation of the grinder. When the motor 17 is actuated, itcauses the housing 14 to move back and forth in a path parallel to theaxis of the wheel being dressed, the tool slide and diamonds moving intoand out of the housing so as to dress a predetermined contour on thewheel being dressed. Trip meme I bers within the housing and mounted onone of the slides automatically reverse the motor at the end of themovement of the housing in either direction.

Base, housing slide guide and housing Reference is had to Figs. 2, 3 and4. The bracket 10 is provided with a rear shelf 1 to which is fixed avertically extending stud 25. The base 13 is rotatably mounted on thestud and is provided with four bolts 26, 27, 28 and 29 which extendthrough oversize holes 29 (see Fig. 2a) in base 13 and can be clampedwhen the base is angularly positioned as desired relative to the wheelbeing dressed. The base is provided with an elongated portion 30 onwhich is mounted a slide guide 31 for supporting the housing 14. Theportion 30 has mounted thereon a tensioning spring having a plate 33which is attached to the bottom of the housing in a manner to bedescribed for urging the housing normally toward the right as viewed inFig. 1 against a cam follower 34 mounted at the end of the extension 35secured to the base 13. This Will be described in detail below.

As shown in Fig. 4, the bottom portion 36 of the housing 14 is providedwith a downwardly extending portion 37 which is received over the slideguide 31 and slidably supported thereon by ball-bearing assemblies 38and 39.

Template slide With reference now to Figs. 3, 4 and 6, there is mountedwithin the housing three slides, a main or template slide carrying thecontour template and a ratio cam for controlling movement of the housingalong the slide guide, an intermediate slide carrying the templatefollower and a second ratio cam, and a tool slide carrying the dressingdiamonds and cooperating with the intermediate slide. As the main slideis moved parallel to the long axis of the housing and normal to the axisof the wheel being dressed, it carries both the template and the ratiocam so as to control movement of the intermediate slide and the movementof the housing.

The main slide 45 is slidably mounted for movement parallel to the longdimension of the housing within the housing by means of the ball-bearingassemblies 46 and 47 (Figs. 3 and 6). Secured to the top of the slide 45is the template 48 which determines the movement of the dressingdiamonds and hence the contour of the grinding wheel being dressed.Mounted on the under side of the slide 45 is the ratio cam 50 whichcontacts the fixed cam follower 34 against which the housing 14 and cam50 are urged by the biasing spring 32.

A rack 51 is mounted on top of the slide 45. It is meshed with a geartrain 17 connected to the prime mover or motor 17. When the motor isenergized, the slide 45 is reciprocated back and forth toward and fromthe wheel being dressed. The motor is reversed by mechanism not shownwhen the dogs 52 and 53 contact microswitches (not shown) to open andclose the switches.

It will be appreciated that as the slide and ratio cam 50 are moved backand forth since biasing spring 32 urges the cam against the follower 34,the housing is forced to move back and forth parallel to the axis of awheel 54 being dressed.

Tool and intermediate slides With reference now to Figs. 3, 4, and 6, atool slide 60 is slidably mounted and supported by ball-bearingassemblies 61 and 62. A biasing spring 63 urges the slide inwardly ofthe housing 14 against a ratio cam and slide in a manner to bedescribed. The slide 60 carries at its outer end the dressing tools 15and 16. A boot 64 provides a dust protector for the slide.

An intermediate slide 70 is slidably mounted within the housing 14 bymeans of ball-bearing assemblies 71 and 72. It has mounted at one end acam follower 73 which contacts the contour edge of the template 48. Atthe other end of the slide 70 is the ratio cam 74 which is contacted bythe follower 75 on the tool slide.

A biasing spring 76 urges the slide 70 and follower 73 against thetemplate 48.

All of the slides described above operate in parallel planes, one abovethe other. As shown in Fig. 7, the various slide movements are shown bythe double headed arrows while the heavy arrows show the force of thebiasing spring.

The above arrangement permits the main slide and tool slide to beclosely spaced, thus reducing the Width of the housing along thedirection of the axis of the wheel to be dressed.

Operation When it is desired to dress a grinding wheel, the work pieceis removed from between the centers of the grinding wheel apparatus. Mydresser is then lifted into place by means of the eye hooks 18 and 19.The female centers 11 and 12 are engaged by the grinder centers and theshelf adjusted to the proper plane by the adjusting screw 20.

When the unit is properly positioned, the motor 17 is energized and, asa result, the slide 45 is reciprocated in a direction toward and fromthe centers. The housing is moved parallel to the axis of the wheelbeing dressed due to contact between the follower 34 and ratio cam 50.The degree of movement is determined by the angle of the inclinedsurface on the ratio cam 50.

At the same time as the template 48 moves across follower 73 of theintermediate slide, the diamonds are moved in and out of the housing 14and normal to the movement 'of the housing. The result of the movementof the housing and the tools is that the tools follow a contourdetermined by the contour of the template.

The advantages of this dresser over any other dresser so far built isthat it can be used on machines where no space can be found for mountinga dresser permanently on the machine. The dresser can be easily removedand placed beside the grinder during the grinding operation and put backon the grinder when needed and precisely located back at its initialposition without any ditnculty. The dresser is fully automatic as far asdressing operations are concerned and no skilled operators are requiredfor even the most complex dressing operations. This present design isprimarily intended for dressing grinding wheels, for gas turbine shaftprofiles, and for grinding complex profiles where it is absolutelynecessary to obtain a good finish. By means of grinding the profilesrather than any other type of machining, the turbine shafts can be madelighter and still equally strong or stronger by obtaining a good surfacefinish of the material so that no highly stressed surface will appeardue to tool marks and the like.

I claim:

1. A grinding wheel dressing apparatus comprising a bracket having apair of spaced centers secured thereto and a supporting shelf, a slideguide mounted upon said shelf, a housing slidably mounted on said slideguide for movement parallel to the axis of a wheel to be dressed, a mainslide movable in one direction within said housing and normal to themovement of said housing, a template mounted on one surface of said mainslide and a ratio cam mounted on the opposite surface of said mainslide, a cam follower fixed to said shelf and engaging said ratio camfor controlling movement of said housing, a tool slide on said housingand movable into and out of said housing and parallel to the movement ofsaid main slide, and an intermediate slide movable transversely of themovement of said main slide and said tool slide and having a follower atone end thereof engaging said template and a ratio cam at the other endthereof engaging said tool slide for controlling movement of said toolslide, said slides having movement in parallel planes, a rack connectedto said main slide and a prime mover mounted on said housing andengaging said rack for moving said main slide.

2; A grinding wheel dressing apparatus comprising a bracket having .apair of spaced aligned centers secured thereto and a supporting shelf, ahousing slidably mounted on said shelf for movement parallel to the axisof a wheel to be dressed, a main slide movable in one direction withinsaid housing and normal to the movement of said housing, a templatemounted'on one surface of said main slide and a ratio cam mounted on theopposite surface of said slide, a pin fixed to said shelf and engagingsaid ratio cam, a tool slide movable into and out of said housing andparallelto said main slide, and means connected between said tool slideand said template for controlling movement of said tool slide, saidslides having movement parallel to each other in parallel planes, andmeans for moving said main slide.

3. A grinding wheel dressing apparatus comprising a base having a pairof centers secured thereto for supporting said apparatus in the positionnormally occupied by a work piece on a grinding apparatus, a housingslidably mounted on said base for movement parallel to the axis of awheel to be dressed, a main slide movable in one direction within saidhousing and normal to the movement of said housing, a template mountedon one surface of said main slide, means fixed to said base and engagingsaid slide for controlling movement of said housing, a tool slidemovable into and out of said housing and parallel to said main slide andclosely spaced therefrom, and an intermediate slide movable transverselyof said main slide and said tool slide and having means engaging saidtemplate at one end thereof and means at the other end thereof engagingsaid tool slide, said slides moving in parallel planes, and a primemover connected to said main slide for moving said main slide and meansfor biasing said slides against each other and said fixed means. a

4. A grinding wheel dressing apparatus comprising a bracket having apair of spaced aligned centers secured thereto for supporting saidapparatus on a grinding wheel assembly, a supporting shelf on saidassembly, a base rotatably mounted upon said shelf, a housing slidablymounted on said base for movement parallel to the axis of the grindingwheel being dressed, a main slide movable in one direction within saidhousing and normal to the movement of said housing, a template mountedon one surface of said main slide and a ratio cam mounted on theopposite surface of said slide, a pin fixed to said base and extendingthrough said housing and engaging said ratio cam, means for biasing saidhousing and ratio cam against said pin, a tool slide movable into andout of said housing and parallel to said main slide, and an intermediateslide movable transversely of said main slide and said tool slide andhaving a cam follower engaging said template at one end thereof and aratio cam at the other end thereof engaging said tool slide, means forbiasing said intermediate slide against said template and said toolslide against said intermediate slide, and a prime mover connected tosaid main slide and mounted on said housing for causing movement of saidhousing and tool slide.

5. A grinding wheel dressing apparatus comprising a bracket having apair of spaced aligned centers secured thereto for supporting saidapparatus in the position of a work piece on a grinding wheel assembly,a rotatable base on said bracket, a housing slidably mounted on saidbase for movement parallel to the axis of a wheel to be dressed, a mainslide movable in one direction Within said housing and normal to themovement of said housing, a template mounted on one surface of saidhousing and an elongated triangularly shaped ratio cam mounted on theopposite surface of said slide, a pin fixed to said base and engagingthe inclined edge of said ratio cam, a tool slide movable into and outof said housing and parallel to said main slide and closely spacedtherefrom, and an intermediate slide movable transversely of said mainslide and said tool slide and having a cam follower engaging saidtemplate at one end thereof and a ratio cam at the otherv end thereofcontrolling movement of said tool slide, the ratio cam of saidintermediate slide extending beyond the end of said tool slide, saidtool slide having a cam follower positioned between said last ratio camand the cam follower on said intermediate slide, a rack connected tosaid main slide and a prime mover engaging said rack for moving saidmain slide and mounted on said housing.

6. A grinding wheel dressing apparatus comprising a bracket having apair of spaced aligned stock centers secured thereto and a supportingshelf extending therefrom, a base on said shelf, an elongated housingslidably mounted on said base for movement parallel to the axis of aWheel being dressed, said housing extending beyond said base and awayfrom said stock centers, and means on said bracket engaging the grindingwheel apparatus for adjusting the position of said base, a main slidemovable in one direction within said housing and normal to the movementof said housing, a template mounted on one surface of said main slideand a ratio cam mounted on the opposite surface of said main slide,means fixed to said base and engaging said ratio cam for controllingmove ment of said housing, a tool slide movable into and out of saidhousing and parallel to said main slide, and an intermediate slidemovable transversely of said main slide and said tool slide and havingconnections between said slides for controlling movement of said toolslide, and a prime mover engaging said main slide for moving said mainslide and mounted on said housing.

7. A grinding wheel dressing apparatus comprising a bracket having meansfor supporting said apparatus between the centers of a grinding machinefor holding a work piece on a grinding machine, a rotatable base on saidbnacket, and adjusting means on said bracket for adjusting the positionof said base, a housing slidably mounted on said base for movementparallel to the axis of a wheel to be dressed, a main slide movable inone direction within said housing and normal to the movement of saidhousing, a template mounted on one surface of said housing and a ratiocam mounted on the opposite surface of said slide, means fixed to saidbase and engaging said ratio cam to control movement of said housing, atool slide movable into and out of said housing :and parallel to saidmain slide, and an intermediate slide movable transversely of said mainslide and said tool slide and connected between said slides forcontrolling movement of said tool slide, and means connected to saidslides for causing movement of said slides and said housing.

8. A grinding wheel dressing apparatus comprising a bracket having meansfor supporting said apparatus between the centers of a grinding wheelapparatus in a position occupied by a work piece during grindingoperations, a rotatable base mounted on said bracket for rotation about"a vertical axis, means on said bracket for rotating said bracket abouta horizontal axis, a housing slidably mounted on said base for movementparallel to the axis of a wheel to be dressed, a main slide movable inone direction within said housing and normal to the movement of saidhousing, a template mounted on said slide, a tool slide movable into andout of said housing and parallel to said main slide, and an intermediateslide movable transversely of said main slide and said tool slide andconnected between said main and tool slides for controlling movement ofsaid tool slide, said slides moving in parallel planes, and a primemover engaging said main slide for moving said main slide and mounted onsaid housing.

9. A grinding wheel dressing apparatus comprising a bracket having apair of spaced stock centers secured thereto and a supporting shelf, aslide guide mounted upon said shelf, a housing slidably mounted on saidslide guide for movement parallel to the axis of said stock centers, amain slide movable in one direction within said housing and normal tothe movement of said housing, a template mounted on one surface of saidmain slide and thereof engaging said tool slide for controlling move- 10ment of said tool slide, said slides moving in parallel planes, a rackconnected to said main slide and a prime mover mounted on said housingand engaging said rack fortmoving said main slide.

References Cited in the file of this patent UNITED STATES PATENTS2,134,607 Harley Oct. 25, 1938 2,220,647 Harley Nov. 5, 1940 2,658,501Hoglund Nov. 10, 1953

